Lots of prepositions in English are close in meaning; e.g. in and on. There are some general rules that are quite easy; e.g., in = inside and on = on top, but there are some quirks that are much harder. For example, in the farm, on the farm and at the farm. There is no real reason why "in the farm" isn't good English, but it isn't. The other two are fine. When you get to that level of using prepositions, you just have to know what word attracts what preposition. It takes time. Good luck.